Pressure-reducers



April 25, 1961 L. PERAs 2,981,281 PRESSURE-REDUCERS Filed Aug. 4, 1958 I "I e, e 3 2 \S \C 5 2O rl i. l f

y N y '5- l2 s /V/ f 8` f4 \'r v 4 26 'Zll 'Z3 36g 35 -BQ- Bo` 3e INVENToR. La a len loe r a. s l BY I 'm //n-v )7M vh@ PRESSURE-REDUCERS Lucien Pras, Billancourt, France, assignor to Regie Nationale des Usines Renault, Billancourt, France Filed Aug. 4, 1958, Ser. No. 752,913 Claims priority, application France Aug. 19, 1957 1 Claim. (Cl. 137-505.317)

The present invention relates to improvements in or relating to devices for reducing the pressureV of gaseous fluids, these improvements consisting essentially insubstituting pneumatic means for the metal springs usually provided for exerting a predetermined adjustment pressure on-the Valve controlling the flow of fluid through the. device, the aforesaid adjustment pressure being obtained, according to this invention, by compressing a certain volume of air.

To this end, the pneumatic means according to this invention comprises essentially a cylinder in which a piston adjustable in the axial direction is slidably mounted and adapted to exert the desired adjustment pressure tending -to open the valve of the pressure-reducer, through the medium of an air cushion and on another member of the pistonor flexible diaphragm type which is rigidly connected to said valve and subjected, on its face opposite to said air cushion, to the fluid under reduced pressure conditions.

According to a specific form of embodiment of this invention leading to the complete elimination of any spring means from the pressure reducer, the aforesaid valve is normally kept in its seated position by a deformable elastic biasing member.

As the pressure reducer is designed for delivering expanded fluid ata pressure lying within a predetermined and relatively wide range of pressures, it will be readily understood that theadjustrnent pressure of the valve may be obtained by so dimensioning the aforesaid pneumatic means as to-ensure a proper safety of operation of the device.

The advantageous properties of a pressure-reducer according to this invention are also derived from theuse of elastic packings of the type formed with flexible/lips ensuring a highly reliable fluid-tightness in the chamber constitutingt'ne air cushion in the pneumatic device.

On the whole, the fact that all springs are definitely eliminated constitutes an important safety factor in the operation of the device. It is known that the springs. of conventional pressure-reducing apparatus are particularly I' liable to corrosion so that after al relatively shorttime of operation they become altered andtheir initial elasticitygis impaired; as` a consequence,V Y sudden failures are' most likely to occur and addl themselves to the un,-y relabltr. andmaintanaue requirements. of theseedef vices. p

The improvements constituting the subject-matter of the present invention will appear more clearly from the following description o-f a typical form lo-f embodiment of a pressure-reducing device vconstructed according to the teachings of this invention and illustrated diagramf i the pressure-reducing device;

matically in axial section by way of example inthe single ligure of the attached drawing forming part of this specication. t

In the drawing, the body 1 of the device is formed with a plurality of pipe-connections having the followy ing purposes: the reference numeral 2 denotes the Vpipe l Abers 1,2- and 21.

king a suitable knurled handle 33. s

provided withl a dome-shaped top A, 2,981,28 1` Patented Apr. 25, 1961v for connecting the pressure-reducer to the source of fluid under pressure; 3 is the outlet pipe having connected thereto the apparatus utilizing the fluid under expanded p-ressure conditions; 4 is the pipe for connecting the pneumatic' device controlling the valve 5 of the pressure-reducer; 6 is the pipe for introducing this valve 5 which also contains a deformable elastic biasing member 7 of rubber or other suitable plastic material which is interposed between the valve 5-to seat same-and a compression plug 9-for sealing this pipe. The valve 5' is adapted to slide in the bore 10 of ybody 1 and also in the bore 11 o-f a gridiron member 12 inserted in position, through the pipe 4 and constituting a valve seat 8, a.,

toroidal gasket 13 being provided in a` groove of the gridiron member 12 to seal it relative to the body 1.VV

under the plug 9 through a passage 15 formed along theH valve and notches 16 formed in the upper projecting bead 71 of the deformable elastic biasing member 7, whereby the pressure of theuid to be expanded will assistE in seating the valve.

engagement of the circular lip 9.1 of the plugwith the cup-shaped seat '61 formed in the pipe 6, as shown, thisr engagement taking place with a certainl elastic pressure resulting from the fact that theV plug is. screwed horne- 12 under the valve seat and communicates permanently pressure-reducer throughY with the outlet pipe 3 of the the radial passage 18 of said gridiron member, the annular space 19 provided between the lower portion thereof and the body 1, and also through: the passage 20 formed in this body. l

The pneumatic device controlling the, Valve 5 corn-v prises acylinder 21 screwed-in the pipe 4 and adapted when mounted on the oneY hand to lock thepbo'ttom-portionof the gridiron member 12in position in thebody 1 and on the other-hand to secure a deformable elastic diaphragm 22y by clamping bead 23 between registering of rubber 5 is screwed, as shown.V

Thus, the diaphragm constitutes therv upper end wallf;

comprises on its.outer periphery. a

sealing lips l26,. 28 adapted the. former .26V to seal the `inside of. the lower;l portion Aof thej gridiron member, that'is,v the/face4 thereof` which is subfjected throughjthek passage 27 tol thle'pressure of` the ex-vr devic is operating, and theother* 28 to seal the upper end of the chamber 29 formed in the 1 ,cushiony is built forl adjusting.

of cylinder 21 and pair of opposite flexible panded uid when the cylinder and wherein theV air This air cushion is obtained operable `from the outside by means of a screw 31 extending throughthe bottom of the` cylinder ffl-2l and carry-r This pistonv 30 is member 34 secured byA ascrew 35 andadapted to secure a packing 36 formed providingl a reliable cylinder end opposite to that provided with the diaphragm the pressure of the fluid supplied by they The plug 9 provides a fluid-tight con-Y nection between the pipe 6 and thisrplug 9 due to the,

the aforesaid sealing contact between its toroidal; outer peripheral shoulders of. the twovmemf This elastic diaphragm-22 consistingA or likeadequate material is used for controlling f by displacing a piston 3,0A

with two divergent sealing lips and uni-directional huid-tightness at the f Z2, the outer lip 36I engaging the cylinder Wall and the inner lip 362 the piston wall, as shown.

This pressure-reducing device operates as follows:

Assuming the control handle 33 to be unscrewed cornpletely as shown in the figure, theppiston 30 bears on the bottom 32 of the cylinder. -Ther chamber 29 is filled with air at the atmospheric pressure due to the provision of a passage 37 connecting the inner space of the cylinder with the surrounding atmosphere; on the other hand, if

the pressure in this space were below the atmospheric value, air at the atmospheric pressure would be admitted therein through notches 38 formed in the bead of packing 36 of which the outer lip 361 may yield slightly and act as a valve, as shown.

If at this time thepipe Zof the pressure-reducer is connected to the outlet of a supply of compressed air, for example, the pressure above the seat S'will rise but no fluid flow will occur as the` valve is seated as already explained. The pressure-reducer acts then like a closed cock.

kIf the control handle 33 is rotated to cause the piston 30 to rise in the body 1, an air cushion of gradually increasing pressure builds up in the chamber 29. At a certain moment this pressure will become capable of pushing the diaphragm 22 to unseat the valve 5. The air from the supply will then flow through the outlet pipe 3 through the path already explained hereinabove.

Under these conditions, the valve is responsive to two opposite assemblies vof forces. yThe iirst assembly results fromnthe action of the air supply pressure acting thereupon, from the elastic force of` deformable elastic biasing member 7, and iinally'from the expanded pressure acting on the upper face of diaphragm 22. The other assembly results from the action of the expanded pressure exerted on the underside of the Valve and from the force transmitted to the diaphragm 22 by the air cushion built up in chamber 29.

`It will be readily understood that whatever pressure may be created in this chamber 29 between predetermined limits, there is an equilibrium of forces permitting such a flow of air through the valve that the pressure after this valve remains stable at a value lying between zero and the supply pressure, whereby the apparatus, will maintain in the pipe 2 and towards the `load apparatus connected ,thereto a predetermined expanded pressure.

`If the air cushion inochamber 29 is compressed to a l higher degree, theforcetending to unseat the valve will.

be further'increased and the expanded pressure will be increased accordingly. If on the contrary this ,air cushion is compressed toa lower degree, the Vexpanded` pressure decreases.` v

It will be noted that the plug 9 has a safety and check hole `39 formed therethrough. In fact,`if the plug were unscrewed while the pressure-reducer is connected to the supply network the air willlescap therethrough after a Y few turns, thus warning the operator.

A hole 40 is alsoformed through the' lateral rwall ofV pipe 4 to act, as in the.case of hole 39, as a safety device in case' the cylinder 21 wereunscrewed beforeutting off the air supply connected to vpipe 2. V.The escapeof air through this hole40,vl/ouldwarnthe operator before the cylinder is unscrewed completely.`- ,Of course, this form, of. embodiment han a a' 1 construed as limiting the field of the invention as many modifications and alterations may be brought thereto without departing from the spirit and scope vof the invention as set forth in the appended claim; thus, the deformable diaphragm may be replaced by a piston provided with a rod connected to the valve and with suitable packing means.

I claim:

In a uid flow control device, a body having opposing inlet and outlet passages, said body having a bore perpendicularly formed between the passages, said bore having inner and outer ends, a member disposed in the inner end of the bore and defining a valve seat, a movable valve member cooperating with the seat and interposed between the passages, a cap member closing olf the outer end of the bore, a deformable elastic biasing member interposed between the valve and the cap lmember to` urge the valve member into engagement with the valve seat, said valve member being exteriorly formed with a passage communicating the inlet passage with a space between the check member and the cap member whereby the pressure of the uid of the inlet vpassage will act on the check member to assist in seating the valve, passage means communicating the valve seat behind the valve member with the outlet passage, a cylinder having opposing inner and outer ends and secured at its inner end to the body and disposed in axial alignment with the valve member, a deformable elastic diaphragm, means inner end of the cylinder provided with the diaphragm,`

'air passage means through the outer end of the cylinder in communication with the atmosphere, a control handle carried by the outer end of the cylinder and having an operating portion disposed through the outer end and in engagement with the piston for moving the piston toward the diaphragm, said piston and the diaphragm defining an air Vchamber in the cylinder, said packing having peripheral notches formed therein for allowing atmospheric air to enter said air Vchamber through the passage in the end wall of the cylinder whereby said chamber encloses an air cushion and the r'piston when moved towardthe diaphragm gradually increases the pressure of the air cushion to unseat Vthe valve'. o A

References Cited in the file of this patent VUNITED STATES PATENTS 

